ABSTRACT
alpha1-Acid glycoprotein (AGP) showed multiple peaks on separation using capillary electrophoresis in a chemically modified capillary with dimethylpolysiloxane at slightly acidic conditions. We analyzed glycoforms of AGP species after separation by ion-exchange chromatography, Con A affinity chromatography, and Cu(II)-chelating affinity chromatography. The AGP species thus obtained were digested with N-glycosidase F, and the released carbohydrate chains were analyzed by high-performance liquid chromatography after labeling with 3-aminobenzoic acid. The results afforded basic information on the contribution of carbohydrate chains to the separation mechanism of glycoforms of AGP by capillary electrophoresis. In addition, we describe an easy method for AGP analysis in serum samples using the electrokinetic injection.
Subject(s)
Carbohydrates/chemistry , Electrophoresis, Capillary/methods , Glycoproteins/blood , N-Acetylneuraminic Acid/chemistry , Orosomucoid/analysis , Protein Isoforms/blood , Carbohydrate Sequence , Chromatography, Liquid/methods , Glycoproteins/chemistry , Humans , Models, Chemical , Molecular Sequence Data , Protein Isoforms/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
Comparative studies concerning glycoform analysis of sialoglycoproteins by capillary electrophoresis were performed using a few separation modes hitherto reported. Glycoprotein samples examined in the present study were successfully separated to their respective glycoforms using surface-modified capillaries commercially available for capillary gas chromatography in the running buffer near their isoelectric points. The analysis times were less than 50 min and reproducibilities in migration times were excellent (less than 2.0% RSD for both run-to-run and day-to-day analyses). We present a method for the glycoform analysis of alpha1-acid glycoprotein in sera by simple pre-treatment as an application. The present technique will become one of the general methods for the evaluation of glycosylation heterogeneity of commercially available glycoprotein drugs.
Subject(s)
Electrophoresis, Capillary/methods , Glycoproteins/chemistry , N-Acetylneuraminic Acid/analysis , Glycoproteins/isolation & purification , Glycosylation , Isoelectric FocusingABSTRACT
Apparatus for high-resolution synchrotron radiation photoelectron spectroscopy combined with high-resolution medium-energy ion scattering, named 'SORIS', has been developed for simultaneous investigations of electronic states and atomic structures on surfaces. For this purpose, a compact vacuum-ultraviolet beamline of photon energy from 5 to 700 eV has been designed for the small storage ring 'Aurora' installed at Ritsumeikan University. Owing to the small electron-beam size in the storage ring, an energy resolution E/dE of >5000 can be obtained.
ABSTRACT
The concentration of metallothionein in mouse tissues after administration of ascorbic acid was determined by the Cd-hem method. The concentration of metallothionein in the liver was increased significantly after an intraperitoneal injection of L-ascorbic acid at the dose of 1000 mg/kg. A simultaneous injection of cycloheximide inhibited the increase of the metallothionein concentration. Mortality of mice injected with a lethal dose of cadmium was decreased significantly by the pre-injection of L-ascorbic acid. All of these results indicate that metallothionein is induced in the liver after the administration of ascorbic acid.
